Such machines have the disadvantage that the unconnected connecting noses of the descending hooks often unintentionally engage the draw knife of the rising knife box, which creates operating errors.
In recognition of this situation, German Pat. No. 1,299,258 among others, developed a single-shank hook which is characterized in that two superposed connecting noses for the lifting knives are provided at both ends of a two-arm lever which is secured rotatably on the one of the hook legs and which must be swung against the action of a restoring force from its central position, in which both noses can reach engagement with their ends and the associated knives, through the knife engagement in one nose so that the other nose lies outside of the affected zone of the other knife. With this design, an unintentional suspension of the noses on the knives has been avoided. However, this hook is composed of several components and forms a high-mass part which because of its inertia does not permit speed increase.
German Pat. No. 75,878 discloses a three-nose, single-shank hook for a double-lift open-shed Jacquard machine. This machine has lifting knives to which the hooks with their noses controlled are joined. The hooks are moved laterally by means of guide grates so that they are not carried along by the second lifting knife during their axial operating movement. For this purpose the entire hook shank consists of the same resiliently flexible material.